Seal for solid formaldehyde products



UNITED STATES OLIVER J'.- BERG. OF OAK PARK, ILLINOIS.

SEAL FOR SOLID FORMALDEHYDE PRODUCTS.

No Drawing.

To 11/] whim/1.12 may (once-I'M.

lie it known that I, Omvrm J. Bane, a citizen of the United States, residing at Oak Park, Cook county, Illinois, have invented certain new and useful Improvements Relating to Seals for Solid Formaldehyde Products, of which the following is a specification.

It is common practice to fumigate for disinfecting purposes with formaldehyde vapors. and among other methods of operation; to employ fumigators comprising a heating unit and a receptacle containing a formaldehyde product in solid form, the application of the heat to the container volatilizing the formaldehydeserious diilieulty has existed in sealing the formaldehyde product against its deterioration through the lapse of time, which deterioration consists chiefly in the further polymerization and hardening of the formaldehyde, and the concentration of the formaldehyde through the evaporation of moisture in the product, whereby the product sometimes becomes quite hard, sometimes falls to powder, and sometimes is otherwise either destroyed or injured.

It is the prime object of the present invention to provide a seal or preserving layer, coat or covering for the formaldehyde product which effectively avoids the impairment of the formaldehyde product through aging, and by simple, cheap and easily applied means. I

An illustration of the solid formaldehyde product herein referred to is what is commonly known to the tradeas paraformaldehyde containing, for instance, sixty-five per cent. of polymerized formaldehyde and thirty-five per cent. of water. The proportions and composition vary, however, in different products and the present invention is not limited to a solid formaldehyde product of any particular kind. In practice this product is poured into cans or other containers while in a liquid condition and allowed to'harden. The desideratum is to provide a seal for the exposed top surface of the product in the container.

Heretofore it has been common practice to pour a layer of liquid paraffin upon the top surface of the formaldehyde product for the purpose of securing the same against the deleterious changes indicated hereinabove. Such coating, however, as the sole Specification of Letters Patent.

Patented Mar. 15, 1921.

Application filed February 7, 1920. Serial No. 357,026.

sealing means is not satisfactory. One reason for this is that it is almost impossible to obtain so perfect a coating on the top surface of the product with paraffin or the like as not to leave air holes, and secondly,

owing to the contraction of the formaldepose the entire top surface of the formaldehyde product.

The seal of my present invention comprises two parts or features; the first being a substance having the property of preventing the deleterious changes in the formaldehyde product mentioned, and servin also as a partial seal against evaporatiori and avoldlng the exposure of any materially large surface of the product even should openings occur in the second sealmg part or feature; and the second part or feature having the property of preventing ob ectionable loss of formaldehyde through its evaporation.

The first part or feature of my complete seal mentioned contains a relatively large amount of glycerin and a relatively small amount of ammonium stearate, and preferably also a relatively quite small amount of stearic acid, when in the preferred form of substance which I employ. In making thls substance I take about twenty-threeand-one-half parts by Weight of glycerin (C H Q about three-and-one-half parts by weight of stearic acid (0, 11, 0 and about one-and-one-half parts by weight of say an approximately twenty-seven per cent. solution of ammonia (NH,,) in water (H O). These three substances are mixed together by heating and stirring, and, owing to the chemical reactions which take place, the resultant mass consists of glycerin and ammonium stearate, (C, H O,.NH,) and a relatively small amount of stearic acid. I prefer to have an excess of stearic acid but the seal would be effective without such excess or even with an excess of ammonia.

Thls mixture has the consistency of fairly th1ck paste when cool. It is applied by warming it and pouring it upon the formaldehyde product in the container and allowing it to harden.

The ammonium stearate is a form .of

thickening agent which I prefer to use in this connection, but the invention is not limited to a base of that particular kind. So far as I know, glycerin is the most satisfactory available substance having the peculiar properties desired in a seal of this kind for such formaldehyde products. I have discovered that other polyhydric alcohols and some carbohydrates exhibit corresponding properties in various degrees, and therefore the invention is not strictly limited to glycerin, although I consider it the most advantageous substance for the purpose described.

The second part or feature of the seal complete may be a layer of paraffin or the like upon the layer of the glycerin-containing mixture hereinabove described. It maybe any suitable Waxy or other substance which has the property of preventing evaporation of the formaldehyde and water in the formaldehyde product. It is pointed out that the first layer mentioned, while preventing deterioration of the formaldehyde product through chemical or physical changes incident to aging, does not'in itself avoid all loss of material through the evaporation of formaldehyde and water. So long as the glycerin-containing sealing element covers the surface of the formaldehyde product the product will remain in its proper condition for use, but through evaporation of both water and formaldehyde the bulk will in time become less.

The second feature of the sealis therefore provided to prevent this loss of material through evaporation.

It is pointed out, however, that this second sealingelement adapted to prevent evaporation does not need to be a wax-like or gummy coating as hereinabove mentioned, but may consist of the cover of the can itself, as Where the can is provided with a screw cap, friction cap, etc., Well known in the art, or it may be a tight box around the container, or a wrapping of oiled or otherwise treated paper around the container. In View of these teachings of the desirability of preventing evaporation, various other means for the purpose will readily suggest themselves to those skilled in able lycerin.

formaldehyde product and a preserving layer therefor which includes glycerin and a thickening substance providing, when mixed together, a mass of paste-like consistency.

3. A solid formaldehyde product and a preserving layer therefor comprising a relatively large amount of glycerin and a relatively small amount of a salt of a fatty acid of high molecular weight.

i. A solid formaldehyde product and a preserving layer therefor comprising a relatively large amount of glycerin and a relatively small amount of ammonium stearate.

5. A solid formaldehyde product and a preserving layer therefor comprising a relatively large amount of glycerin, a relatively small amount of ammonium stearate, and a relatively quite small amount of stearic acid.

6. A formaldehyde product and a covering element'therefor including a polyhydric alcohol having the property of substantially maintaining the product against material deterioration and against material loss throu h evaporation.

7. K solid formaldehyde product and a covering therefor which comprises glycerin and a thickening substance, and also means.

for maintaining the product against material evaporation.

8. A solid formaldehyde product and a covering therefor comprising'a mixture of a relatively largeamount of glycerin and a relatively small amount of ammonium stearate, and means for maintaining the product substantially against evaporation; I

. OLIVER J. BERG. 

